HELSINKI, Finland (AP) - In what it calls a first in international air travel, Finnair says it will let its frequent fliers check in using text messages on mobile phones.

The program begins in October and is open to the airline's Finnair Plus cardholders. It will let those passengers who have only carry-on luggage go directly to the departure gate, bypassing ordinary check-in procedures. Like other passengers, they will have to go through a metal detector and security check.

Once passengers have activated the service, they will automatically receive a check-in text message from Finnair before a flight with details, including the seat number. A passenger need only send a reply to confirm the seat assignment.

The text message service will apply to all international flights leaving from Helsinki and Stockholm.

Finnair said its check-in using SMS, or Short Message Service, is the first worldwide to work on all mobile phone models and all networks without charges.

Other airlines offer similar services that notify passengers of flight delays, schedules or available seats.